The present invention relates generally to radio systems and more particularly to an improved back end for radio signal control.
Radio systems are known in the art of communications between communication devices. One type of radio receives analog radio signals through an antenna where the analog signals are passed to a front end of the radio. The front end communicates with back-end circuitry to assist the back-end to convert the received analog signal into audio or data information. The back-end is controlled in part by a micro-processor, micro-controller, or other type of processing circuitry.
As an analog radio signal passes through a communications channel, various signal impairments are introduced into the analog signal and interfere with desired radio outputs. This is true whether the analog radio signal is an amplitude modulated (AM) or frequency modulated (FM) signal. Those skilled in the art recognize the existence of signal impairments and past efforts to remove the impairments have not been completely satisfactory.
Regarding removal of the impairments, those skilled in the art have not combined voltage averaging circuitry with a first and second variable voltage averaging circuit, a variable low pass filter, and a variable attenuator to remove impairments from radio transmissions when the control circuits are operating independently upon L+R and Lxe2x88x92R audio signals in the FM mode or in the I and Q demodulation modes when the receiver is operative in the AM mode. Such control is performed upon the analog receiver signals reactive to analog and digital control functions and instructions. Thus, much improvement is possible in existing noise reduction circuitry for radios.
Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.